But I'd like to know what they're comparing with when they say "driver's car". Do they mean, like the M3 that a base Mustang GT beat in Motortrend's comparo? Or the Mercedes AMG that doesn't come close to the ZL1's 'Ring time?

I'd have to guess "Caterham 7" with whatever 200-ish HP engine they're using these days.

No, it's nowhere near as all-around useful as either of the ponycars in question here, but utility isn't the point of a pure "driver's car".